Our list of the twenty richest people of all time includes entrepreneurs, warriors and robber barons. We did not include monarchs, whose wealth could be considered public. Our list is based on scholarly estimates, but obviously remains highly speculative.

You'll notice much of the list come from England and America. Partly this happens because that's where estimates were available. But it's also true that extreme private wealth occurred only several times in history, such as the great lords of England, the Gilded Age, and right now.